"""
/***************************************************************************
Name                 : DB Manager
Description          : Database manager plugin for QGIS
Date                 : May 23, 2011
copyright            : (C) 2011 by Giuseppe Sucameli
email                : brush.tyler@gmail.com

 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/
"""

from qgis.PyQt.QtWidgets import QApplication

from ..info_model import TableInfo, VectorTableInfo, RasterTableInfo, DatabaseInfo
from ..html_elems import HtmlSection, HtmlParagraph, HtmlTable, HtmlTableHeader, HtmlTableCol


class PGDatabaseInfo(DatabaseInfo):

    def connectionDetails(self):
        tbl = [
            (QApplication.translate("DBManagerPlugin", "Host:"), self.db.connector.host),
            (QApplication.translate("DBManagerPlugin", "User:"), self.db.connector.user),
            (QApplication.translate("DBManagerPlugin", "Database:"), self.db.connector.dbname)
        ]
        return HtmlTable(tbl)


class PGTableInfo(TableInfo):

    def __init__(self, table):
        super().__init__(table)
        self.table = table

    def generalInfo(self):
        ret = []

        # if the estimation is less than 100 rows, try to count them - it shouldn't take long time
        if self.table.rowCount is None and self.table.estimatedRowCount < 100:
            # row count information is not displayed yet, so just block
            # table signals to avoid double refreshing (infoViewer->refreshRowCount->tableChanged->infoViewer)
            self.table.blockSignals(True)
            self.table.refreshRowCount()
            self.table.blockSignals(False)

        tbl = [
            (QApplication.translate("DBManagerPlugin", "Relation type:"),
             QApplication.translate("DBManagerPlugin", "View") if self.table._relationType == 'v' else
             QApplication.translate("DBManagerPlugin", "Materialized view") if self.table._relationType == 'm' else
             QApplication.translate("DBManagerPlugin", "Table")),
            (QApplication.translate("DBManagerPlugin", "Owner:"), self.table.owner)
        ]
        if self.table.comment:
            tbl.append((QApplication.translate("DBManagerPlugin", "Comment:"), self.table.comment))

        tbl.extend([
            (QApplication.translate("DBManagerPlugin", "Pages:"), self.table.pages),
            (QApplication.translate("DBManagerPlugin", "Rows (estimation):"), self.table.estimatedRowCount)
        ])

        # privileges
        # has the user access to this schema?
        schema_priv = self.table.database().connector.getSchemaPrivileges(
            self.table.schemaName()) if self.table.schema() else None
        if schema_priv is None:
            pass
        elif not schema_priv[1]:  # no usage privileges on the schema
            tbl.append((QApplication.translate("DBManagerPlugin", "Privileges:"),
                        QApplication.translate("DBManagerPlugin",
                                               "<warning> This user doesn't have usage privileges for this schema!")))
        else:
            table_priv = self.table.database().connector.getTablePrivileges((self.table.schemaName(), self.table.name))
            privileges = []
            if table_priv[0]:
                privileges.append("select")

                if self.table.rowCount is not None and self.table.rowCount >= 0:
                    tbl.append((QApplication.translate("DBManagerPlugin", "Rows (counted):"),
                                self.table.rowCount if self.table.rowCount is not None else QApplication.translate(
                                    "DBManagerPlugin", 'Unknown (<a href="action:rows/count">find out</a>)')))

            if table_priv[1]:
                privileges.append("insert")
            if table_priv[2]:
                privileges.append("update")
            if table_priv[3]:
                privileges.append("delete")
            priv_string = ", ".join(privileges) if len(privileges) > 0 else QApplication.translate("DBManagerPlugin",
                                                                                                   '<warning> This user has no privileges!')
            tbl.append((QApplication.translate("DBManagerPlugin", "Privileges:"), priv_string))

        ret.append(HtmlTable(tbl))

        if schema_priv is not None and schema_priv[1]:
            if table_priv[0] and not table_priv[1] and not table_priv[2] and not table_priv[3]:
                ret.append(HtmlParagraph(
                    QApplication.translate("DBManagerPlugin", "<warning> This user has read-only privileges.")))

        if not self.table.isView:
            if self.table.rowCount is not None:
                if abs(self.table.estimatedRowCount - self.table.rowCount) > 1 and \
                        (self.table.estimatedRowCount > 2 * self.table.rowCount
                         or self.table.rowCount > 2 * self.table.estimatedRowCount):
                    ret.append(HtmlParagraph(QApplication.translate("DBManagerPlugin",
                                                                    "<warning> There's a significant difference between estimated and real row count. "
                                                                    'Consider running <a href="action:vacuumanalyze/run">VACUUM ANALYZE</a>.')))

        # primary key defined?
        if not self.table.isView:
            if len([fld for fld in self.table.fields() if fld.primaryKey]) <= 0:
                ret.append(HtmlParagraph(
                    QApplication.translate("DBManagerPlugin", "<warning> No primary key defined for this table!")))

        return ret

    def getSpatialInfo(self):
        ret = []

        info = self.db.connector.getSpatialInfo()
        if info is None:
            return

        tbl = [
            (QApplication.translate("DBManagerPlugin", "Library:"), info[0]),
            (QApplication.translate("DBManagerPlugin", "Scripts:"), info[3]),
            ("GEOS:", info[1]),
            ("Proj:", info[2])
        ]
        ret.append(HtmlTable(tbl))

        if info[1] is not None and info[1] != info[2]:
            ret.append(HtmlParagraph(QApplication.translate("DBManagerPlugin",
                                                            "<warning> Version of installed scripts doesn't match version of released scripts!\n"
                                                            "This is probably a result of incorrect PostGIS upgrade.")))

        if not self.db.connector.has_geometry_columns:
            ret.append(HtmlParagraph(
                QApplication.translate("DBManagerPlugin", "<warning> geometry_columns table doesn't exist!\n"
                                                          "This table is essential for many GIS applications for enumeration of tables.")))
        elif not self.db.connector.has_geometry_columns_access:
            ret.append(HtmlParagraph(QApplication.translate("DBManagerPlugin",
                                                            "<warning> This user doesn't have privileges to read contents of geometry_columns table!\n"
                                                            "This table is essential for many GIS applications for enumeration of tables.")))

        return ret

    def fieldsDetails(self):
        tbl = []

        # define the table header
        header = (
            "#", QApplication.translate("DBManagerPlugin", "Name"), QApplication.translate("DBManagerPlugin", "Type"),
            QApplication.translate("DBManagerPlugin", "Length"), QApplication.translate("DBManagerPlugin", "Null"),
            QApplication.translate("DBManagerPlugin", "Default"), QApplication.translate("DBManagerPlugin", "Comment"))
        tbl.append(HtmlTableHeader(header))

        # add table contents
        for fld in self.table.fields():
            char_max_len = fld.charMaxLen if fld.charMaxLen is not None and fld.charMaxLen != -1 else ""
            is_null_txt = "N" if fld.notNull else "Y"

            # make primary key field underlined
            attrs = {"class": "underline"} if fld.primaryKey else None
            name = HtmlTableCol(fld.name, attrs)

            tbl.append((fld.num, name, fld.type2String(), char_max_len, is_null_txt, fld.default2String(), fld.getComment()))

        return HtmlTable(tbl, {"class": "header"})

    def triggersDetails(self):
        if self.table.triggers() is None or len(self.table.triggers()) <= 0:
            return None

        ret = []

        tbl = []
        # define the table header
        header = (
            QApplication.translate("DBManagerPlugin", "Name"), QApplication.translate("DBManagerPlugin", "Function"),
            QApplication.translate("DBManagerPlugin", "Type"), QApplication.translate("DBManagerPlugin", "Enabled"))
        tbl.append(HtmlTableHeader(header))

        # add table contents
        for trig in self.table.triggers():
            name = '%(name)s (<a href="action:trigger/%(name)s/%(action)s">%(action)s</a>)' % {"name": trig.name,
                                                                                               "action": "delete"}

            (enabled, action) = (QApplication.translate("DBManagerPlugin", "Yes"), "disable") if trig.enabled else (
                QApplication.translate("DBManagerPlugin", "No"), "enable")
            txt_enabled = '%(enabled)s (<a href="action:trigger/%(name)s/%(action)s">%(action)s</a>)' % {
                "name": trig.name, "action": action, "enabled": enabled}

            tbl.append((name, trig.function, trig.type2String(), txt_enabled))

        ret.append(HtmlTable(tbl, {"class": "header"}))

        ret.append(HtmlParagraph(QApplication.translate("DBManagerPlugin",
                                                        '<a href="action:triggers/enable">Enable all triggers</a> / <a href="action:triggers/disable">Disable all triggers</a>')))
        return ret

    def rulesDetails(self):
        if self.table.rules() is None or len(self.table.rules()) <= 0:
            return None

        tbl = []
        # define the table header
        header = (
            QApplication.translate("DBManagerPlugin", "Name"), QApplication.translate("DBManagerPlugin", "Definition"))
        tbl.append(HtmlTableHeader(header))

        # add table contents
        for rule in self.table.rules():
            name = '%(name)s (<a href="action:rule/%(name)s/%(action)s">%(action)s</a>)' % {"name": rule.name,
                                                                                            "action": "delete"}
            tbl.append((name, rule.definition))

        return HtmlTable(tbl, {"class": "header"})

    def getTableInfo(self):
        ret = TableInfo.getTableInfo(self)

        # rules
        rules_details = self.rulesDetails()
        if rules_details is None:
            pass
        else:
            ret.append(HtmlSection(QApplication.translate("DBManagerPlugin", 'Rules'), rules_details))

        return ret


class PGVectorTableInfo(PGTableInfo, VectorTableInfo):

    def __init__(self, table):
        VectorTableInfo.__init__(self, table)
        PGTableInfo.__init__(self, table)

    def spatialInfo(self):
        return VectorTableInfo.spatialInfo(self)


class PGRasterTableInfo(PGTableInfo, RasterTableInfo):

    def __init__(self, table):
        RasterTableInfo.__init__(self, table)
        PGTableInfo.__init__(self, table)

    def spatialInfo(self):
        return RasterTableInfo.spatialInfo(self)
